1. Field of the Invention
Asphalt is an obvious staple of the road builder. Despite its durability under load, it is susceptible to the vagaries of changing weather conditions and temperature, which results in expansion and contraction of the surface.
In areas where the temperature can reach effective, if not actual, freezing levels and, when moisture is present, whether from rain, dew or fog, the rate of expansion of water in cracks, or in areas adjacent the lateral edges of the roadway, may exceed that of the road material. As a result, cracks are generated and pieces of asphalt material can literally be lifted from the roadway.
Repeated flexing due to loads running over the roadway also creates cracks, which may eventuate in the lifting and tearing of pieces of asphalt. The inevitable consequence is the enemy of every car's wheels, tires and suspension, the pothole.
The driving public is increasingly vocal about the condition of the roadways upon which they travel, and government, while attempting to respond, is typically under capitalized, understaffed and under equipped to meet the problem as and where it occurs.
In many communities, government has attempted to kill two birds with one stone by acquiring paving equipment which will lay blacktop the width of a full lane of traffic and hope to use the same rig for repairs. Sadly, one size does not always fit all and most paving equipment is very large, expensive to operate in terms of dollars and man power, and often cumbersome to move about even if it were not.
What those whose task it is to effect asphalt repairs want, and what the present invention uniquely provides, is a highly efficient and maneuverable device for effecting small repairs wherever they occur in a highly cost effective manner.
2. Overview of the Prior Art
Since the memory of man runneth not to the contrary, the patching of asphalt is a labor intensive, and often short term, effort. Who among us has not seen a road crew behind a dump truck with asphalt simmering in the bed. With shovels and brooms in hand the crew fills the area to be patched and, in more modern times, a hand-held tamper of sorts is sometimes used to compact the patch.
The patent art includes several more sophisticated and less labor intensive examples, among them Miller U.S. Pat. No. 4,830,533, which discloses a patching machine which depends from a truck and uses a telescoping conveyor to deliver patching material to a bucket and then a spreader, both of which are on a turntable, rotatable on a vertical axis through 360°. Miller also provides a platform for the operator. Miller lacks the versatility of the present invention in that it can not position the spreader relative to the effected area without positioning the truck in order to locate the conveyor precisely over the effected area.
Other patents of some general interest include Hulicsko U.S. Pat. No. 5,131,788 and Gabriel Jr. U.S. Pat. No. 4,215,949 which use a tamping device, and both drop patching material from a truck hopper. Sterner U.S. Pat. No. 4,678,363 drops material from a bin and sprays binder on it. In his U.S. Pat. No. 4,511,284, he uses air to clean the effected area before dropping material through a manually manipulatable chute. Still other device provides a heater and/or scraper to finish a patch, and several other patents disclose various patching devices over which the present invention constitutes a marked improvement.